Can the metadata that is embedded in the DSD files be manipulated and changed?
Yes, the metadata inside DSD files are easily editable as it is ID3V2 a compliant file (i.e any player that reads both DSF and ID3V2 tags will see the info). The tags, before going up on the NativeDSD servers, were applied using JRIver (a Windows and Mac music player).
You can still edit the tags inside the files with other players (like Audirvana Plus or Roon on the Mac)
or tag programs like MP3tag or Tag&Rename (see more info below).
Currently most of our DSF files also have embedded artwork (but since we started doing this in 2015, some of the early releases may lack this artwork). Most players, renderers and control points find them easily via the web (assuming you haven’t changed the album name with some suffix, etc). If the album artwork does not show up, it is probably due to the fact that your control point isn’t picking up web-based cover art (like your computer is).
You can add or change cover art with the above mentioned players and taggers, or some control points simply need a folder.jpg or cover.jpg to be present in the same folder as the tracks to pick it up.
Easily change the tags to your own liking
Editing metadata on the music download files on Native DSD is very easy. We recommend using a program like Tag and Rename, which you can try for Free and sells for $29, to edit the metadata, change track numbering, cover art, etc.
Or alternatively, on a MAC:
Is there an option to easily convert .DFF to .DSF to add metadata?
DFF to DSF is best done right (by that we mean that some players say they can do it but it goes to PCM in the meantime...that is...wrong).
Linked below is a simple little utility that the author/developer of HQplayer has put together. It changes the header info only (which is the only real difference between DFF and DSF) and thus is fairly quick. This utility was command line only but has been enhanced to be a right-click in Windows Explorer.
Here is the info on DFF to DSF: http://www.signalyst.com/professional.html
The context sensitive ad-on: http://www.computeraudiophile.com/f11-software/dff-dsf-conversion-21715/#post354558
However, DFF files have no metadata, so the subsequent DSF files will start out with none either. Players like JRIver or utilities like MP3TAG or Tag&Rename can help you input tags and some of the process can be done with a set of files (album and artists name, track numbers, etc), but tags unique to each track like track names are currently a manual process. There is one other way, but this is only for albums which you already own in another format (redbook, etc). JRIver has a function called tag paste, and it is as simple as it sounds, assuming the files are both lined up in the same order.